Injectable drug delivery arrangement with controlled delivery cannula position relative to point of delivery

ABSTRACT

A cannula for administration of a medicine to a target location includes a tube with at least one nodule disposed along the circumferential surface and spaced at a defined distance from the distal end of the tube. An arrangement for delivery of a medicine to a target location includes the cannula and a pump fluidly coupled to the cannula. The distal end of the cannula may be inserted into a target location until the nodule reaches a surface that limits a depth of penetration before delivery of the medication.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application61/515,547, which was filed on Aug. 5, 2011, which is included herein byreference in its entirety for all purposes.

TECHNICAL FIELD

This patent disclosure relates generally to systems for the delivery ofmedicine, and, more particularly to structures for controlling the depthof penetration of a delivery cannula relative to a point of delivery.

BACKGROUND

The delivery of medications by injection may be in the form of a singleadministration(s), or a series of administrations that occur atpredetermined intervals over a set time period. Medication can bedelivered using a pump to a cannula that is placed into the target boneor tissue. Pumps for delivering the medication may be, for example, inthe form of a syringe or a primary drug container, that is actuated todeliver a predetermined volume of medicine at set times or timeintervals, or in response to a delivery trigger.

A number of injectable medication delivery applications require theplacement of the delivery cannula remotely from the pump. In suchapplications, the delivery cannula may be fluidly coupled to the pump byflexible tubing, which allows for required placement of the cannula,convenient placement of the pump, and provides flexibility to theclinician to manipulating the medication delivery setup. For example,the pump may be supported on the surface of a table or in a bag, or onthe patient's body itself.

Accurate placement of the cannula requires not only accurate placementfor insertion, but also precise depth insertion. In this regard, it isdesirable that there be minimum interference with the line of sight tothe patient end of the cannula so the medical personnel may clearlyvisualize the penetrating end of the cannula along with the targettissue or bone. Ensuring delivery of medication at the correct depth iscritical to maximizing efficacy of many medications and compliance withindicated route of administration. For example, too deep of penetrationof a cannula may result in intramuscular delivery as opposed to anintended subcutaneous delivery, while too shallow penetration may resultin subcutaneous delivery, as opposed to an intended intramusculardelivery.

SUMMARY

The disclosure describes, in one aspect, a cannula for use in theadministration of a medicine to a target location. The cannula includesa tube having a proximal end and a distal end, a lumen extending betweenthe proximal and distal ends, and an outer circumferential surfacedefining a circumference. At least one nodule is disposed along theouter circumferential surface and spaced at a defined distance from thedistal end of the tube. The at least one nodule may be utilized as depthlimiters to control the depth of cannula insertion at a target location.

In one embodiment, the cannula may be utilized for administration of amedicine to a targeted location into the inner ear. The cannula may beinserted through an ear canal of an ear such that the distal end of thecannula and the at least one nodule are caused to pass through atympanic membrane. The distal end of the cannula may be placed adjacentto or in contact with a target location at the membrane wall of theinner ear such that the at least one nodules limit the insertion depthof the cannula into the wall. The medicine may then be administered tothe target location. The at least one nodule may be sized, shaped,arranged and/or otherwise configured to permit passage through one ormore membranes, such as the tympanic membrane, while not permittingpassage through other membranes, such as the temporal bone lining theinner ear.

The disclosure describes, in another aspect, an arrangement for deliveryof a medicine to a target location. The arrangement includes a cannulaand a pump fluidly coupled to the cannula. The cannula includes a tubehaving a proximal end and a distal end, a lumen extending between theproximal and distal ends, and an outer circumferential surface defininga circumference. The at least one nodule is disposed along thecircumferential surface and spaced at a defined distance from the distalend of the tube.

The disclosure describes, in yet another aspect, a method of deliveringa medicine to a target location. The method includes the steps ofpositioning the distal end of a cannula for insertion into the targetlocation, inserting the distal end of the cannula into the targetlocation until a nodule disposed on the outer surface of the cannulareaches a surface that limits a depth of penetration into the targetlocation, and delivering the medicine through the cannula to the targetlocation.

The disclosure describes, in a further aspect, a method of fabricatingthe cannula comprising the steps of providing a tube, and forming the atleast one nodule on the outer surface of the tube by at least one ofmetal stamping, precision welding, injection molding, needle overmold,adhesion, interference fit, and electrochemical deposition, andcombinations thereof.

BRIEF DESCRIPTION OF THE DRAWING(S)

FIG. 1 is a schematic view of a medicine delivery system according toaspects the disclosure.

FIG. 2 is an enlarged fragmentary isometric view of an end of a cannulaof FIG. 1 according to aspects of the disclosure.

FIG. 3 is an enlarged fragmentary side elevational view of the end ofthe cannula of FIG. 2.

FIG. 4 is an end view of the cannula of FIG. 2.

FIG. 5 is an enlarged fragmentary side elevational view of an end ofanother embodiment of a cannula according to aspects of the disclosure.

FIG. 6 is an end view of the cannula of FIG. 5.

FIG. 7 is an enlarged fragmentary side elevational view of an end ofanother embodiment of a cannula according to aspects of the disclosure.

FIG. 8 is an end view of the cannula of FIG. 7.

FIG. 9 is an enlarged fragmentary side elevational view of an end ofanother embodiment of a cannula according to aspects of the disclosure.

FIG. 10 is an end view of the cannula of FIG. 9.

FIG. 11 is an enlarged fragmentary side elevational view of an end ofanother embodiment of a cannula according to aspects of the disclosure.

FIG. 12 is an end view of the cannula of FIG. 11.

FIG. 13 is an enlarged end view of another embodiment of a cannulaaccording to aspects of the disclosure.

FIG. 14 is an end view of the cannula of FIG. 13.

FIG. 15 is an enlarged fragmentary side elevational view of an end ofanother embodiment of a cannula according to aspects of the disclosure.

FIG. 16 is an end view of the cannula of FIG. 15.

FIG. 17 is an enlarged fragmentary side elevational view of an end ofanother embodiment of a cannula according to aspects of the disclosure.

FIG. 18 is an end view of the cannula of FIG. 17.

DETAILED DESCRIPTION

The invention relates to a device and method for controlling theposition of a medicine delivery cannula, and related methods ofmanufacturing and methods of use. Accurate positioning of a deliverycannula and dispensing of medication to a target location is critical tothe efficacy, compliance, and success of many medical treatments. Thepresent invention provides a device and methodology for targeting thedelivery cannula and the appropriate depth in a target membrane toimprove the administration of such treatments. Utilizing the presentinventions for drug delivery to targeted location may greatly improvethe efficacy of the treatment, ease or simplify the surgical operationof the physician, and decrease the amount of pain or discomfort felt bythe patient. For example, certain treatments must be delivered to theinner ear. Too shallow penetration of a cannula in this sensitivelocation may result in inaccurate or incomplete delivery of themedication while too deep penetration may cause substantial pain and/orharm to the patient. The embodiments of the present invention functionto ensure that the accurate depth for drug delivery is reached, therebymaximizing drug efficacy while maintaining or improving patient comfort.

Turning to FIG. 1, there is illustrated an arrangement 20 foradministration of a medicine. For purposes of this disclosure, the term“medicine” is intended to include a substance or preparation used intreating disease or a health condition, maintaining health, or treating,preventing, alleviating, or curing of disease or a health condition. Theterm “medicine” may include, for example, gaseous, liquid, and powderform pharmaceutical treatments. The device may be used in a number oflocations for drug delivery such as, for example, the inner ear of apatient, as illustrated in FIG. 1.

The arrangement 20 includes a pump 22 that is fluidly connected to acannula 24 for administration of the medicine to a target location 26,such as within a tissue or within a bone. The pump 22 may include anyappropriate administration device, such as, by way of example only, asyringe, or some other container the holds the medicine for delivery,and may be manually or automatically actuated. The pump 22 provides oneor more of a single administration of medicine, administration ofmedicine over period of time, administration of medicine at controlledintervals, or administration of medication upon manual activation.

The pump 22 may be fluidly coupled directly to the cannula 24, or, asshown in FIG. 1, the pump 22 may be fluidly coupled to the cannula 24 bya secondary cannula or tubing 28, which serves as a medicine pathway tothe delivery cannula 24. The tubing 28 may be of any appropriate designand material. By way of example, the tubing 28 may be formed ofpolyurethane tubing or another suitable material. The proximal end 30 ofthe tubing 28 is securely coupled to the pump 22, while the distal end31 of the tubing 28 is coupled to a proximal end 32 of the cannula 24 byany appropriate method, such as an interference fit or partial,controlled dissolution of the material of the tubing 28. A control clamp34, such as the illustrated hemostat, may be provided to further controlflow of medicine through the arrangement and may, optionally, be used tocontrol flow. It will be appreciated that the flexibility and length ofthe tubing 28 allow the pump 22 to be disposed at a location that is adistance from the cannula 24. In this way, the pump 22 may be disposedon a support surface, such as a table (not illustrated), carried in apouch or pocket (not illustrated), or disposed directly on or in bodytissue (not illustrated). Alternatively, as stated above, a syringe orother primary drug container may be utilized to initially store thetreatment and dispense it for delivery to the targeted location.

The delivery cannula 24 includes a tube 40 with a proximal end 32, wherea drug treatment may be introduced, and a distal end 42, where a drugtreatment may be dispensed, and a lumen 44 (see FIG. 2) extendingbetween the proximal and distal ends 32, 42 along a longitudinal axis.The distal end 42 may be blunt, as illustrated in FIGS. 1-4, or beveledto a sharp tip, as illustrated in FIGS. 5-18, for example. The outersurface 46 of the cannula 24 is generally circumferential, and defines acircumference 48. In use, the distal end 42 of the cannula 24 isinserted into the target location 26 such that medicine from the pump 22may be delivered through the tubing 28 (if included) and the lumen 44 ofthe cannula 24 to the target location 26.

The cannula 24 may be made of a number of materials, such as, forexample, plastic or metal. The cannula 24 may be a rigid cannula or asoft cannula. In at least one embodiment, the cannula 24 is a rigidsteel cannula with no bevel.

According to a feature of this disclosure, the cannula 24 includes aninjection depth regulating arrangement in the form of at least onenodule 50 that is disposed along the circumferential outer surface 46and spaced from the distal end 42 of the tube 40. When the distal end 42of the cannula 24 is inserted into the target location 26, the nodule 50will contact a surface 52 to control the penetration depth of thecannula 24. It will be appreciated that surface 52 may be a surface ofthe target location 26 for medicine delivery, or the surface 52 may bean alternate surface. By way of example only, if the target location 26is bone, the surface 52 may be the surface of a tissue covering thebone. Thus, the nodule 50 provides a positive stop for the clinician/enduser/patient to press against the surface 52 for administration of themedicine, with the distance 54 of the nodule 50 from the distal end 42of the cannula 24 and the at least one nodule 50 functioning to limitthe penetration into the target location 26.

The one or more nodules 50 may be located on the outer surface of thecannula 24 at any desirable location along its longitudinal axis. Forexample, the one or more nodules 50 may be located at or near the distalend 42 of the cannula 50 in one or more embodiments, while one or morenodules 50 may be located at or near the proximal end 32 of the cannula50 in one or more alternate embodiments. By way of example only, invarious embodiments, the distance 54 of the nodule 50 from the distalend 42 of the cannula 24 may be on the order of 0.1 mm, 0.2 mm, or 0.5mm in a blunt tipped cannula 24, or any other appropriate distance. Itwill be appreciated that the distance 54 may be adjusted in a cannula 24having a sharpened tip.

The cannula 24 may include one nodule 50, or a plurality of nodules 50.The cannula 24 may include two nodules 50 as shown, for example in FIGS.5-6, or three nodules 50 as shown, for example in FIGS. 7-8, or fournodules 50 as shown, for example in FIGS. 9-10, or any number of nodules50. It will be appreciated that the nodules 50 may be substantiallyevenly spaced about the circumference, as shown in FIGS. 5-10, or theymay be unevenly spaced (not shown). Alternately, the nodules 50 may bedisposed substantially adjacent one another about the circumference, asshown, for example, in FIGS. 11-12. Furthermore, the nodules may bedisposed substantially adjacent one another about the circumference suchthat they effectively form an outer ring. Moreover, the nodules 50 maybe disposed about the circumference in a plane disposed at a right angleto the axis of the cannula 24, as illustrated, or, for example, in aplane disposed at an angle to the axis of the cannula 24 (not shown).Nodules 50 disposed in an angled plane may be particularly useful, forexample, when the cannula 24 is to rest against the target location 26at an angle. Angular positioning of the distal end 42 of the cannula 24at a target location 26 may alternatively be achieved by positioning oneor more nodules distal or proximal to the location of one or more othernodules, such that they are located at different distances from the samereference point on the cannula. When two or more of these unevenlyspaced nodules come in contact with the target location, they cannula 24will be caused to rest at an angle to the target location.

The height 56 and outer shape of the nodules 50 may have the same ordifferent cross-sectional profiles in embodiments of the cannula 24. Thenodules 50 illustrated in FIGS. 1-12 are substantially hemisphericallyshaped, although they may be alternately shaped. For example, thenodules 50 may have the shape of a cone, triangle, pyramid, or a spherehaving a segment removed, or the shape of a segment of a sphere, or theshape of an ellipse. The nodules 50 may be oval, square, rectangular, ortrapezoidal. Those of skill in the art will appreciate, however, thatsmooth structures may minimize opportunities for the nodules 50 to catchon tissue as the distal end 42 of the cannula 24 is moved toward or awayfrom the target location 26, and may minimize opportunities for anypossible damage to such tissue or the target location 26.

By way of further example, the nodules 50 may have a ramped shape, thatis, they may include a base end 60 that increases to a peak end 62 atwhich the nodule 50 displays the greatest height 56, as shown, forexample, in FIGS. 13-18. In this regard, the nodules 50 may be disposedwith the base end 60 of one nodule 50 substantially adjacent the peakend 62 of another nodule 51, as shown, for example, in FIGS. 13-14.Alternately, ramp-shaped nodules 50 may be disposed substantiallyparallel to the axis of the cannula 50, as shown in FIGS. 15-18. It willbe appreciated that such a ramped structure may facilitate insertion ofthe cannula 50 during placement or retraction of the cannula 50 duringremoval of the cannula 50 following the administration of medicine. Forexample, a cannula 24 having the ramp-shaped nodules 50 placed asillustrated in FIGS. 15 and 16 may facilitate movement of the distal end42 of the cannula 24 completely through a tissue before reaching atarget location 26, or removal following administration if theramp-shaped nodules 50 are placed as illustrated in FIGS. 17 and 18. Forexample, in the administration location as illustrated in FIG. 1, thedistal end 42 of the cannula 24 may be moved through the tympanicmembrane 64 before reaching the ultimate target location 26. Theutilization of ramp-shaped nodules 50 may assist in this placement orremoval.

It will be appreciated by those of skill in the art that the extent towhich the cannula 24 penetrates into the target location 26 isdetermined by distance 54 of the nodule 50 from the distal end 42 of thecannula 24, the height 56 of the nodule 50 (measured perpendicularly tothe axis of the cannula 24), and the shape of the nodule 50, as well asthe compressibility of the target location 26. Thus, the design of thecannula 24 may be tailored to the application and target location 26 forwhich it will be utilized.

The cannula 24 may be fabricated by any appropriate method. The nodules50 may be pre-formed as part of the cannula 24 or may be added to thecannula 24 by a number of manufacturing methodologies. For example, theone or more nodules 50 may be welded, such as by micro-welding, to thetube 40. In such configurations, the material of the welded nodules 50may be a similar/identical material from that of the cannula 24. In atleast one embodiment, the one or more nodules 50 are steel noduleswelded to a rigid steel tube 40. Alternatively, the nodules 50 may bemounted, attached, formed, or otherwise fixed to the tube 40 by methodsknown in the art including metal stamping, precision welding, injectionmolding, needle overmold, adhesion, interference fit, andelectrochemical deposition, among others. Some fabrication methods, forexample, precision welding, may be done in the absence of oxygen or inan inert atmosphere to prevent oxidation of the cannula 24. The choiceof fabrication method may be contingent on application and the materialof the cannula 24 and of the nodules 50.

According to one method, multiple nodules 50 are laser welded to theouter surface 46 of the tube 40 in an atmosphere of inert gas. The laseris utilized to smooth the intersection of the nodules 50 at the outersurface 46 after forming each nodule 50 or on completion of all nodules.The cannula 24 may then be abrasive bead blasted or deburred by anyappropriate method. Preferably, each cannula 24 is inspected to ensureboth weld strength and integrity of the lumen 44.

In summary, the cannula 24 containing the one or more depth limitingnodules 50 may be used in a number of different applications. Generally,the cannula 24 may be used to deliver drug treatments to a targetlocation 26 at a particular depth. For example, the cannula 24 may beutilized for drug delivery into bone, such as the temporal bone forinner ear delivery of drug. Similarly, the cannula 24 may be utilizedfor intramuscular delivery, intradermal delivery, subcutaneous delivery,or any other indicated route of administration, where the delivery is tobe targeted at a particular depth. Inasmuch as the cannula 24 includesdiscrete nodules 50, the nodules 50 do not obstruct or only minimallyobstruct the distal end 42 of cannula 24 during placement, providingmedical personnel with a line of sight and hence enhanced opportunityfor accurate placement.

It will be appreciated that the foregoing description provides examplesof the disclosed system and technique. However, it is contemplated thatother implementations of the disclosure may differ in detail from theforegoing examples. All references to the disclosure or examples thereofare intended to reference the particular example being discussed at thatpoint and are not intended to imply any limitation as to the scope ofthe disclosure more generally. All language of distinction anddisparagement with respect to certain features is intended to indicate alack of preference for those features, but not to exclude such from thescope of the disclosure entirely unless otherwise indicated.

Recitation of ranges of values herein are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein, and eachseparate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context.

Accordingly, this disclosure includes all modifications and equivalentsof the subject matter recited in the claims appended hereto as permittedby applicable law. Moreover, any combination of the above-describedelements in all possible variations thereof is encompassed by thedisclosure unless otherwise indicated herein or otherwise clearlycontradicted by context.

1. A cannula for use in the administration of a medicine to a targetlocation, the cannula comprising: a tube including a proximal end and adistal end, a lumen extending between the proximal and distal ends, andan outer circumferential surface defining a circumference, at least onenodule disposed along the circumferential surface and spaced at adefined distance from the distal end of the tube.
 2. The cannula ofclaim 1 comprising a single nodule.
 3. The cannula of claim 1 comprisinga plurality of nodules.
 4. The cannula of claim 3 wherein the nodulesare substantially evenly spaced about the circumference.
 5. The cannulaof claim 3 wherein the nodules are unevenly spaced about thecircumference.
 6. The cannula of claim 1 wherein the nodule issubstantially the shape of a cone formed at the circumferential surfaceof the tube.
 7. The cannula of claim 1 wherein the nodule is of asubstantially hemispherical shape.
 8. The cannula of claim 3 wherein thenodules are positioned at substantially the same distance from a distalend of the cannula.
 9. The cannula of claim 3 wherein the nodules arepositioned at two or more distances from a distal end of the cannula.10. The cannula of claim 1 wherein the nodule has a ramped shape. 11.The cannula of claim 10 wherein the nodule includes a base end and apeak end, and the base and peak ends alternate about the circumference.12. The cannula of claim 10 wherein the nodule includes a base end and apeak end, the base end being disposed toward the distal end of the tube,and the peak end being disposed away from the distal end of the tube.13. The cannula of claim 10 wherein the nodule includes a base end and apeak end, the base end being disposed away from the distal end of thetube, and the peak end being disposed toward the distal end of the tube.14. The cannula of claim 1 wherein the tube is rigid.
 15. The cannula ofclaim 1 wherein the tube is flexible.
 16. The cannula of claim 1 whereinthe distal end of the tube is angled to a point.
 17. The cannula ofclaim 1 wherein the distal end of the tube is not angled.
 18. Anarrangement for delivery of a medicine to a target location, thearrangement comprising the cannula of claim 1, and a pump fluidlycoupled to the cannula.
 19. A method of delivering a medicine to atarget location, the method comprising the steps of: positioning thedistal end of the tube of claim 1 for insertion into the targetlocation, inserting the distal end of the tube into the target locationuntil the nodule reaches a surface that limits a depth of penetrationinto the target location, and delivering the medicine to the targetlocation.
 20. A method of fabricating the cannula of claim 1, the stepscomprising providing a tube forming the at least one nodule on the outersurface of the tube by at least one of metal stamping, precisionwelding, injection molding, needle overmold, adhesion, interference fit,and electrochemical deposition.